Arya, AnilPandey, LokeshGaur, AnuragKumar, VijaySharma, A.L.2024-01-212024-08-132024-01-212024-08-132021-09-069781000470512978036769425810.1201/9781003141761-5https://kr.cup.edu.in/handle/32116/3670This chapter is dedicated to the electrolyte that is a crucial component of any device. Electrolyte plays a dual role in the device, acts as a carpet for electrolyte ions, and also separates the electrodes to avoid short-circuiting or explosion. Initially, the characteristics parameter and selection criteria for the electrolyte will be discussed. Then, the organic electrolytes have been discussed followed by a focus on emerging novel gel/solid polymer electrolytes for application in battery and supercapacitor. The performance of the battery and supercapacitor is shown for different electrolytes. � 2022 Taylor & Francis Group, LLC.en-USBook chapterhttps://www.taylorfrancis.com/books/9781003141761/chapters/10.1201/9781003141761-5